JPH05209280A - Method for controlling cvd film - Google Patents

Abstract

PURPOSE:To securely control the thickness of a CVD film on a wafer as a substrate, at the time of forming the CVD film on the wafer by a seed-fed type CVD apparatus, by measuring the change of the intensity of an infrared ray from the surface of the wafer or its emissivity. CONSTITUTION:A wafer as a substrate to be treated is placed in a reaction chamber of a seed-fed type CVD apparatus. The inside of the reaction chamber is evacuated and the wafer is heated as well as a reaction gas introduced into the reaction chamber to form a CVD film on the surface of the wafer. In this stage, the change of the intensity of an infrared ray from the wafer or its emissivity is regularly monitored and measured. By the measured value therefrom, the thickness of the CVD film is found, and when the film thickness reaches the desired certain value, the supply of the reaction gas is stopped, and the thickness of the CVD film is controlled always to the uniform desired value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single-wafer CVD apparatus which is a semiconductor manufacturing apparatus, and more particularly to a CVD film control method using the single-wafer CVD apparatus.

[0002]

2. Description of the Related Art FIG. 2 is an explanatory view of a conventional method. In FIG. 2, t _s is a time point when film formation is started with each set value of flow rate, pressure and temperature as a parameter, t _s is an end time point thereof, and t ₁ is a process (period) thereof. In this conventional method, the film thickness is controlled by adjusting the time with the preset values of the reaction gas flow rate, the production pressure and the production temperature as parameters.

[0003]

The above-mentioned conventional method has a problem that it is a passive method of adjusting the time and that the film thickness between batches cannot be made uniform.

[0004]

In order to solve the above-mentioned problems, the method of the present invention is to install a wafer in a reaction chamber as shown in FIG. A single-wafer CVD apparatus that heats and forms a CVD film on the surface of a wafer is characterized by controlling the infrared ray intensity change or emissivity from the wafer to control the formed film thickness.

[0005]

[Operation] The intensity of infrared rays radiated from the wafer surface during CVD film formation (which is said to be the change in emissivity due to the interference between the formed film and the wafer substrate) depends on the generated film thickness. Change. This change in infrared intensity is
Since there is a correlation with the generated film thickness, the generated film thickness can be obtained by measuring the change in infrared intensity.

[0006]

EXAMPLE FIG. 1 (A) is a diagram showing the relationship between infrared intensity and film thickness in the method of the present invention, and FIG. 1 (B) is a time chart of film thickness increase and reaction gas flow in the film forming step by the method of the present invention. is there. In this embodiment, after the valve is opened to start the reaction gas flow and the film formation is started, the infrared intensity from the wafer is constantly monitored by an infrared intensity measuring device, and the measuring device measures the change point a of the infrared intensity with respect to the required film thickness. Is measured, and when the change point a is measured, the valve is closed to stop the flow of the reaction gas and stop the film formation.

In this way, by the output of the infrared intensity measuring device, the valve is closed and the flow of the reaction gas is stopped, whereby the single-wafer type C
The film thickness of the VD film can be automatically controlled, a constant film thickness can always be generated, and the film thickness between batches can be made uniform.

[0008]

As described above, according to the present invention, the single-wafer type C
Since this is a method of controlling the film thickness generated by measuring the infrared intensity change or emissivity from the wafer in the VD device, the film thickness between batches can be made uniform.

[Brief description of drawings]

FIG. 1A is a diagram showing the relationship between infrared intensity and film thickness in the method of the present invention. (B) is a time chart of film thickness increase and reaction gas flow in the film formation step by the method of the present invention.

FIG. 2 is an explanatory diagram of a conventional method.

Front page continuation (72) Hideo Ishizu Inventor Hideo Ishizu, Shinjuku-ku, Tokyo 2-9-9 Kokusai Electric System Service Co., Ltd. (72) Inventor Shuichi Nakamura 7-9-1 Kawabe-cho, Ome-shi, Tokyo Green Park Wakakusa No. 105

Claims (2)

[Claims] 1. A wafer is placed in a reaction chamber, and the wafer is heated while flowing a reaction gas under reduced pressure in the reaction chamber,
A method for controlling a CVD film, characterized in that, in a single-wafer CVD apparatus for producing a CVD film on a wafer surface, the produced film thickness is controlled by measuring an infrared intensity change or emissivity from the wafer. 2. After starting the flow of the reaction gas and starting the film formation, the infrared intensity from the wafer is constantly monitored by an infrared intensity measuring instrument, and this measuring instrument indicates the change point (a) of the infrared intensity with respect to the required film thickness. The CVD film control method according to claim 1, wherein the measurement is performed, and when the change point (a) is measured, the reaction gas flow is stopped to stop the film formation.